[wildcards] Consider quick fix: convert UNUSED_CATCH_STACK to wildcard

[pq]

Given:

f() {
  try {
  } on String catch (e, stackTrace) {
    print(e);
  }
}

we might consider a fix that produces:

f() {
  try {
  } on String catch (e, _) {
    print(e);
  }
}

in addition to the one that currently removes the unused clause:

f() {
  try {
  } on String catch (e) {
    print(e);
  }
}

Question: is there value in adding a convert UNUSED_CATCH_STACK to a wildcard fix?

@kallentu @bwilkerson

[dart-github-bot]

Summary: The issue proposes a quick fix to convert the UNUSED_CATCH_STACK lint to a wildcard, which would simplify the lint's implementation and potentially improve performance.

[bwilkerson]

I don't see any value in having a wildcard in a non-required location. While the language makes it valid (presumably for consistency), I wouldn't want to see it in my code. (I'd actually want an unnecessary_stack_trace_parameter (or some such) warning.

The only time I'd allow a wildcard is for something like

f() {
  try {
  } on String catch (_, stackTrace) {
    print(stackTrace);
  }
}

where the exception isn't used but has to be provided in order to capture the stack trace.

If we had a warning when the exception parameter isn't referenced (which we don't have but might consider adding now) we could have a fix to convert it to a wildcard.

[pq]

Great. Agreed. Thanks!